Method and closing device for producing sausage-like products

ABSTRACT

Method and closing device for producing sausage-like products with a flexible tubular or pouch-like wrapper, wherein the various stages of the closing process include constriction of the wrapper, elongation of the braid, setting and closure of the clamp fastener, which can be controlled in a partially autonomous manner by means of a programmable control unit.

This invention relates to a method for producing sausage-like productswith a tubular or bag-shaped packaging casing, where the (unilaterallyclosed) packaging casing is first of all filled with filling and issubsequently crimped, then there is produced a neck portion of thedesired length, which is free from filling, and the neck portion freefrom filling is finally closed by setting and closing at least oneclosure clip. The invention also relates to a closing device forproducing sausage-like products with a tubular or bag-shaped packagingcasing comprising means for crimping the packaging casing, means forproducing a neck portion free from filling by spreading the crimpingmeans, and means for setting and closing closure clips.

It is known to package for instance sausage meat for edible sausages orcement and sealing compounds in tubular films or bags. This is done in aknown manner (DE-OS 27 30 603) in that the tubular or bag-shapedpackaging casing is filled with filling by a filling machine. At the endof the filling operation or shortly before the same, the filling machineemits a pulse by means of which a closing operation is initiated. Thesame starts with the filled packaging casing being first of all crimpedto form a short neck by closing two pairs of crimping shears.Subsequently, the two pairs of crimping shears are axially moved apart(spread) in longitudinal direction of the sausage (and displace fillingwhich is present at this point), so that between the two pairs ofcrimping shears there is obtained a neck of the desired length, which isfree from filling. Thereupon, a lower clip lever with a die in which twoopen closure clips are disposed swivels below the neck portion free fromfilling, whereas at the same time an upper clip lever with a stampswivels towards the closure clips from the top and closes the same. Theneck has then been closed by two closure clips disposed one beside theother and can possibly be cut through between these two closure clips.After the closing operation the machine parts involved therein move backto their starting position, and a new working cycle starts with thefilling operation.

The pairs of crimping shears and the clip lever are mechanically coupledwith each other, e.g. by shafts, cam plates or the like, so that theirmovements are forcibly coordinated during the closing operation.

Proceeding from this prior art it is the object underlying the inventionto increase the productivity during the production of sausage-likeproducts with tubular or bag-shaped packaging casing.

In accordance with the invention, the solution of this object consistsin a method as described above, where the partial operations of closingincluding crimping the packaging casing, of elongating the neck obtainedas well as of setting and closing the closure clip can at least partlybe controlled independent of each other.

The gist of the invention consists in omitting the rigid forcedcoordination of the movements when closing the packaging casing in favorof a flexible control or regulation of the individual movements adaptedto the respective product. It is thus possible to ensure that thespreading operation e.g. in the case of raw sausages or sealing compoundand cement sausages takes place more slowly and in a controlled way,whereas the setting and closing of the closure clips takes place muchquicker than has so far been common practice. In this way, theproductivity during the production of such products is increasedconsiderably.

An advantageous variant of the method is characterized in that thepartial operations of closing are controlled by product-specificprograms. In this way, the movements of the machine parts involved inthe closing operation can be stored in a program for each product, sothat these movements can easily be recalled for the production of therespective product. The product-specific properties, on which depend themovements stored in the program, are for instance the kind of fillingand the kind of packaging casing material, the final diameter and thefinal weight of the finished product, and the kind of closure clipsused.

In accordance with the invention, the solution of the object furthermoreconsists in a device as stated above, where the means for crimping thepackaging casing, the means for elongating the neck, and the means forsetting and closing closure clips can at least partly be controlledindependent of each other. The device originates from the same basicidea as the method mentioned above and can accordingly be used forperforming this method. The device thus creates the conditions for aconsiderable increase in productivity during the production ofsausage-like products. The means for crimping the packaging casing andfor forming a neck portion free from filling by spreading the crimpingmeans, which are provided in the device, can be the known pairs ofspreadable crimping shears. Suitable means for setting and closingclosure clips are the known clip levers provided with stamp and die.

The device preferably includes a control unit with which the means forcrimping the packaging casing, the means for elongating the neckobtained (by spreading the crimping means), and the means for settingand closing the closure clips are connected for a variably coordinatedactuation.

The control unit is preferably programmable such that it can be fed withproduct-specific programs in which the optimum movements for therespective product are stored. In this way, the device can easily beadapted to the respective product to be produced without conversions, bya simple change of program.

In a preferred embodiment of the device, the means for crimping thepackaging casing, the means for elongating the neck, and the means forsetting and closing closure clips have electric motors as controllabledriving elements. Particularly suitable electric motors are linearmotors or synchronous motors. By using electric motors as drivingelements, the entire control of the closing operation can be effectedelectrically or electronically.

An alternative embodiment of the method is characterized in that themeans for crimping the packaging casing, the means for elongating theneck, and the means for setting and closing closure clips have hydraulicelements as controllable driving elements. A common advantage ofhydraulic elements and of the aforementioned electric motors is the factthat their movement can exactly be controlled at any time, so that notonly the beginning of the individual movements, but also the respectivemovement itself can exactly be predetermined.

The invention will now be explained in detail with reference to threeexamples by means of the figures of the drawing, wherein:

FIG. 1 shows an inventive closing device (including control unit) in aschematic perspective representation;

FIG. 2 shows a movement diagram optimized for a certain type of productfor the crimping drive, the spreading drive, the upper clip lever andthe lower clip lever of a closing machine;

FIG. 3 shows the movement diagram from FIG. 2 for another type ofproduct; and

FIG. 4 shows the movement diagram for a third type of product.

The diagrams shown in FIGS. 2 to 4 refer to the device shown in FIG. 1for closing filled, tubular or bag-shaped packaging casings. This deviceas a whole designated with 10 has two pairs of crimping shears 11, 12,which can be closed and opened by a crimping drive in the form of acrimping cylinder 14, so as to first gather the filled packaging casingto form a neck and then release the same again upon elongating the neckand setting the clip or clips. In addition, the pairs of crimping shearscan temporarily be moved away from each other axially in longitudinaldirection of the sausage by means of a spreading drive 16, so as toproduce a longer neck portion of the desired length, which is free fromfilling.

Furthermore, the device includes a lower clip tool with a die 18 foraccommodating one or more closure clips, which can be moved below thecasing neck by a lower closing cylinder 20, and upon closing the closureclips can be moved back again. There is furthermore provided an upperclip tool with a stamp 22, which is actuated by an upper closingcylinder 24 and cooperates with the die 18 of the lower clip tool, inorder to close the closure clips. Subsequently, the die 18 and the stamp22 are moved back to their starting positions. The closure clips arecoherently—in a not represented, but known way—withdrawn from magazinesin the form of clip coils 26 and (by cutting them off) introduced intothe die 18.

The closing device thus includes four driving elements, which effect theabove-described closing operation: the crimping cylinder 14 for openingand closing the pairs of crimping shears 11, 12, the spreading drive 16for spreading the two pairs of crimping shears 11, 12, as well as theupper and the lower closing cylinder 24 and 20, respectively. Thesedrives are not coupled with each other by a common control drive, suchas a cam plate, but are subject to the (electric, pneumatic orhydraulic) control by a control unit 28, whose functional connectionwith the drives is represented in broken lines in FIG. 1.

The closing operation is initiated by a pulse sent by the fillingmachine to the closing machine at the latest when the packaging casingis filled with the desired quantity of filling. The closing operationstarts with the crimping cylinder 14 of the closing machine 10 closingthe two pairs of crimping shears 11, 12 according to a preprogrammedmovement, so that the packaging casing is crimped to form a—at firstshort—neck.

Subsequently, the spreading drive 16 starts to work and spreads the twoclosed pairs of crimping shears 11, 12 by axially moving them away fromeach other in longitudinal direction of the sausage. There is obtained aneck portion of the desired length, which is free from filling. Thismovement, too, is program-controlled and depends for instance on theparameters casing friction, tautness of the product, etc.

After producing the neck portion free from filling, the same is closedby means of two closure clips disposed one beside the other. For thispurpose, the lower closing cylinder 20 presses the die 18, in which theclosure clips are accommodated, below the casing neck, whereas the upperclosing cylinder 24 with the stamp 22 at the same time moves towards theclosure clips from the top and closes the same. The upper and lowerclosing cylinders 20, 24 are activated such that stamp 22 and die 18start to move at the same time. However, the die 18 reaches its maximumstroke before the stamp 22. The die 18 carries the two closure clips sofar into the closing area that the neck is disposed inside the stillopen closure clips. Only after this will the stamp 22 reach its finalposition and close the two closure clips by forming them around theneck. Thereupon, stamp 22 and die 18 remain in their terminal positionsfor a predeterminable period, in order to minimize the spring-back ofthe closed closure clips. The closing movements of the two tools, andthus the program which determines the movement of the upper and thelower closing cylinder 20, 24, depend for instance on the desired smoothrunning and the deformability of the closure clips used.

Upon closing the two closure clips, the two pairs of crimping shears 11,12 can be opened again, and the two closing tools 18, 22 can be movedback to their starting position. These movements are not restricted byany product parameters, so that they can be performed with the maximumpossible speed. As soon as the pairs of crimping shears 11, 12 arecompletely open, they can be moved towards each other by the spreadingdrive 16, where a damped slow-down of the movement prevents the twopairs of crimping shears from striking against each other. After the twopairs of crimping shears 11, 12 as well as the closing tools 18, 22 havereturned to their starting positions, the closing operation isterminated.

The individual movements are programmed once and can be recalled againfor the production of the same product via a program code.

The diagrams in FIGS. 2 to 4 represent the regulating distances s of thefour driving elements involved in the closing operation as a function oftime for three different products which differ from each other in theirdiameter and their mass or the kind of filling. In this way, thedependence of the movements on the diameter and the mass of the finishedproduct or the filling becomes clear.

In the diagrams of FIGS. 2, 3 and 4 the ordinate each shows theregulating distance s for the crimping cylinder 14, the spreading drive16, the stamp 22, and the die 18. The abscissa is the time axis.

The diagrams in FIG. 2 refer to a sausage casing having a diameter of 35mm and a weight of 80 g, which sausage casing is filled with boiledsausage meat.

The sausage underlying the diagrams in FIG. 3 is also filled with boiledsausage meat, but this sausage has a diameter of 120 mm and finally aweight of 2.5 kg. The larger diameter and the larger final weight of theproduct result in larger regulating distances for all four drives and—asthe acceleration of the drives is limited—also longer regulating times.

The sausage underlying the diagrams in FIG. 4 has the same diameter andthe same final weight as the sausage shown in FIG. 3, but it is notfilled with boiled sausage meat, but with raw sausage meat. Since rawsausage meat has a different consistency as compared to boiled sausagemeat, the crimping operation and the spreading operation cannot beperformed as quickly as with boiled sausage meat. During the crimpingoperation, the pairs of crimping shears 11, 12 therefore take more time,despite the same regulating distance, for being moved from the openedinto the closed position. The same is true for spreading the pairs ofcrimping shears. Since for the sausages shown in FIGS. 3 and 4 the sameclosure clips are used, the upper stamp 22 and the lower die 18 followthe same speed profile in both cases. Measured from the beginning of thecrimping operation, the movement of the upper and of the lower toolstarts in FIG. 4 at a later time as compared to FIG. 3, as the upper andthe lower closing cylinder 24 and 20, respectively, are only startedwhen the spreading drive 16 has moved the two pairs of crimping shears11, 12 into the maximally spread position, which takes longer than inthe example of FIG. 3; in addition, the spreading drive 16 is also onlystarted when the two pairs of crimping shears 11, 12 are completelyclosed towards the end of the crimping operation. This takes also longerin FIG. 4 than in FIG. 3.

As the comparison of the movement diagrams, in particular those of FIGS.3 and 4, shows, the individual activation of the individual drivesresults in a considerable saving of time as compared to the case whereall these drives are coupled with each other, for instance via a singleshaft or cam plate. For if the drives in the examples underlying FIGS. 3and 4 were jointly driven by one shaft, not only the crimping and thespreading operation would take more time in FIG. 4 than in FIG. 3, butalso the closing tools driven by the same shaft, so that the setting andclosing of the closure clips would be delayed unnecessarily.

What is claimed is:
 1. A method for producing sausage-like products witha tubular or bag-shaped packaging casing, where the unilaterally closedpackaging casing is first of all filled with filling and is subsequentlycrimped, then there is produced a neck portion of the desired length,which is free from filling, and the neck portion free from filling isfinally closed by setting and closing at least one closure clip, whereinthe operations of crimping the packaging casing, elongating the neckobtained, and setting and closing of the closure clip are eachcontrolled independently of each other.
 2. The method according to claim1, wherein the operations are controlled by product-specific programs.3. A closing device for producing sausage-like products with a tubularor bag-shaped packaging casing, comprising means (11, 12, 14) forcrimping the packaging casing, means (16) for forming a neck portionfree from filling by spreading the crimping means, and means (18, 20,22, 24) for setting and closing closure clips, wherein the means (11,12, 14) for crimping the packaging casing, the means (16) for spreadingthe crimping means, and the means (18, 20, 22, 24) for setting andclosing closure dips are controlled independently of each other.
 4. Thedevice according to claim 3, wherein the device includes a control unit(28) to which the means (11, 12, 14) for crimping the packaging casing,the means (16) for spreading the crimping means, and the means (18, 20,22, 24) for setting and closing closure clips are connected.
 5. Thedevice according to claim 4, wherein the control unit is programmable.6. The device according to claim 3, wherein the means (11, 12, 14) forcrimping the packaging casing, the means (16) for spreading the crimpingmeans, and the means (18, 20, 22, 24) for setting and closing closureclips have electric motors as driving elements.
 7. The device accordingto claim 6, wherein the electric motors are linear motors.
 8. The deviceaccording to claim 6, wherein the electric motors are synchronousmotors.
 9. The device according to claim 3, wherein the means (11, 12,14) for crimping the packaging casing, the means (16) for spreading thecrimping means, and the means (18, 20, 22, 24) for setting and closingclosure clips have pneumatic or hydraulic elements as driving elements.